(CNN) --Democratic presidential candidate Howard Dean sparked criticism from his rivals Saturday after invoking the Confederate flag in an outline of his election strategy.

"I still want to be the candidate for guys with Confederate flags in their pickup trucks," the former Vermont governor said in an interview published Saturday in the Des Moines Register. "We can't beat George Bush unless we appeal to a broad cross-section of Democrats."

It was at least the second time Dean publicly used the Confederate flag to describe Southern voters who often vote for Republicans.

Dean previously used the flag reference during a February meeting of the Democratic National Committee.

At that event, Dean received a rousing ovation from the crowd when he said, "White folks in the South who drive pickup trucks with Confederate flag decals on the back ought to be voting with us, and not [Republicans], because their kids don't have health insurance either, and their kids need better schools too."

All the other Democratic candidates at that time attended that session except Sen. John Kerry of Massachusetts, who was absent for health reasons.

Gephardt, who polls show is in a close race with Dean to win January's Iowa caucuses, wrapped his criticism in patriotism.

"I don't want to be the candidate for guys with Confederate flags in their pickup trucks. I will win the Democratic nomination because I will be the candidate for the guys with American flags in their pickup trucks," Gephardt's statement said.

Lieberman admonished Dean to watch his words.

"Governor Dean ought to be more careful about what he says," he said. "It is irresponsible and reckless to loosely talk about one of the most divisive, hurtful symbols in American history."

Kerry used his statement to illustrate his views on gun control and his support of the NAACP.

"Howard Dean is justifying his pandering to the NRA by saying his opposition to an assault weapons ban allows him to pander to lovers of the Confederate flag," Kerry said in his statement. "It is simply unconscionable for Howard Dean to embrace the most racially divisive symbol in America. I would rather be the candidate of the NAACP than the NRA."

Dean told the National Rifle Association in a 1992 questionnaire that he opposed restrictions on private ownership of assault weapons, and received the NRA's highest ratings when he was governor.

Dean has said he believes gun control laws should be a state matter, a position that might be considered a liability with the liberal base of the Democratic party, which supports federal gun control measures.

Gephardt, the former House minority leader, said Dean appears to believe "that if we sacrifice our support for reasonable gun legislation like the assault weapons ban, we will win the support of those that disagree with us on bedrock Democratic values like civil rights."

But a Dean spokesman called the criticism "a desperate political attack on the part of Governor Dean's opponents."

Spokesman Jay Carson said Dean was trying to explain that Democrats need to broaden their appeal to Southern men, who in recent years have voted Republican in growing numbers. Carson said Dean has been using the flag line since he started campaigning, and that his rivals misconstrued it as support for the Confederate banner.

Dean also released his own statement to clarify his comments.

"I want people with Confederate flags on their trucks to put down those flags and vote Democratic," he said in the statement.

"We have working white families in the South voting for tax cuts for the richest one percent while their children remain with no health care," said Dean. "The dividing of working people by race has been a cornerstone of Republican politics for the last three decades. For my fellow Democratic opponents to sink to this level is really tragic. The only way we're going to beat George Bush is if Southern white working families and African-American working families come together under the Democratic tent, as they did under FDR."

Dean noted that none of his rivals took public offense when he made nearly identical remarks at the earlier meeting of the Democratic National Committee.